Thixotropic compositions



Patented Sept. 16, 1952 Birger W. Nold landr, horits'oh, Scotia, N.

Electric (Jempany, a eorpomtliin NoDt-awinz. Application Deeember 51, 19%,

Eerie! No.

(Cl. Z6040) 8 Gla'ims.

mvennen i 'elaltes tb 'tm'xetmnic compositions, ma mere 1a'ez 'tiz-zuner13; to 'polymerizable thistbn onie ceatmg' endfimng compositifms comrinsing a 'pblymerizeble liquid and a. nller.

A ni-e'mem '0? meme etendineenceuntered in-facto'ry' px'nbneemeenneetfenfwith the use at com vntiefiail armenes 0!- eating rfilling enmieatiens is the exemive drainage Item the coated or'fifle'fi pert aim mevmitsh nae applied. A 56mm e: was firenia ge occurs at robin tern permeate immediately erterthe pm m new :renioved meet the firwtiii tank because 'of the fluid nitui'e 61 the eem'entmnm varnishes gene'mlly emmeyed. This :ai aimge mmmues emu surneiem newest nee evfiplirait'ed to eau's'e the Viscoszw e? the winter; on the suflace er in the intei stic'e's at the tratefi bict t0 tieebme Suifiifitty high 310 enable it t6 xemem m fpbsltifin. It is dbvfiiis mm the name: at the process is even than; ten 61' the vanish lemme away from the th; fif we trate'd part end a surplus cll'ectfi rat the ar fine-wart. resulting in a very name andesinme' ultimate enema tion at :me wiifiieh bueethi oughwt the next. Further aeammge eeeurs during the early stages oi any baking which might be mvbIved, when tm: wmmsn b'afie remaining in the treated iwant meom'es finerenslngly time as the temperatmre :is memeee. This drainage will ecintlnue until m eemeeeme is e" eientl'y high, and has been eurfieienfl? Ion: to cause the van-main t6 "tmm er "skin over due te pray men reaefiaiieot bfl tweet eta-Aether, siren a3 emdehfiliiim, manammn mu adfliti'en new time. 'izmvefitwnal varnishes el se hive a dis afivanwee in that they new am from shit-p eomere and @5208; meme these reg'ieni .mem em.

The net melt s! mankind's e: mating" an: niling in men 2;. manner is a very nneeenennem 1mm tizm 6t tti tat warmer: twig-Infill? applied, only a, fraction being remmea; Fniflirinefe, an undesirably uneven ditflbiitloh 6f the varnish iii the inw't'fltibs ween fit-Ye lif-ffi *6! the metal part results. I

wlflre' the meblem er coating er Biting e1ec mew neviee's, eue'n as, fer examfile, eieetflcal ems 113's ween weaved, the zine-um er material zeta/med utter a meme fl apfieltlfin 1's in most {mm insufliifit t6 inert! e Stflitifi'e having the 2 required lectiiekl bind mememem 'ifi'opeftie's. several su'e'dsfiive gemreeemng -9.hd names are usually'neeeseary, n'dfiirfg eonidlwbly to the cost of the treatment. In thefceee of see "stipetur'es, such as leetfleay cens eeempleve filling becomes impessime efiip1bing the coaiti'ng' and filling compositions heretofore known in the art, not bnly beeang'e otth'e feet that thejneft, Vela,- tile solvent in tnfb'fiiia'ditidn must be expelled after each applleq'tidn, dutal'sb befinse inany voids are sealed air jihejevabnretion bf the solvents. In maxi fifiee -tfis'e vbid earm n be filled by additiomil v'ei'hlsh rii'rdless bi hnw many subsequent tfeatm'enos we applied to the structure. This eeuses the ti'eategl 'structuie to have an 'uneqndl thermal conductivit 'f-fbm one part to another as veil us a much tower wer en heat dissipation fate as comperea with *a completely vein-free feature. in big?! voltage equipment the 'ereeenee 61 wide in the meal tion gives rise to intefimi bi'bna di'eehnre W'ith resulting flteffdnitifin oi the 'fififilhfloifi.

"Certain of the above amenities teen neenmn nated by the use '6? oeeliededwenmess Varnihes. This term is intended in the present diselosure to sever ementum bf matter which are pel menzable hiflds Sub's'tahtiflhr er inei't, vemme solvents seen are these mean can- Ventienal varn shes, ind 'Whlh, by the unevenratidn of su table etelyets. h1g3? be caused to pelymerize to form Substantially infpisible fund immune materials Without the neeeesity 6! tin:- ing up oxygen tram 51% an enewlbhout iefmme volatile products. 7

Since the eenveiien the fluid to the Hard, in'fiu'sible stage wear: with aime of he 1S of the weight or material apmiea an we zen-neg 'o'i' filling uperatidn, it is ibis 1131B; 5y ffls bf proper techmqize; net mm #6 flll bfimifl'et'ei? an the spaces in an even eture. 1411611 3% Q @311, but also to ma'intem this dnditlibn eitlifii'ddefifly during the curin mtiompfovidefl that Sub stantially no drainage '0! varnish oews'fluflng the euringpreease,

Many p: the solventlees varnishes of the tyne with which the present invention is eeneerned, and which will be hereinafter more telly deem ibed, eoinfiriefilfl? fluid, non-volatile corniiositibns. Tnererere, 1n eam afison with the converimeimi vmnshe 'concmriine highly viscous or solid bases, these solventless varnish compositions suffer the disadvantage that they do not become increasingly viscous on standing at room temperature by the evaporation of a volatile inert solvent. As a result, an open structure coated or filled with such a solventless varnish composition will continuously suffer loss of the varnish by. drainage after it has been withdrawn from the treating tank and before it has been polymerized by heating. Furthermore, in common with the conventional varnishes containing appreciable amounts of solvents, many of the solventless varnishes have the disadvantage that during the early stages of the curing process their viscosity is substantially reduced, further aggravating the drainage problem. The difficulties arising out of this property of the solventless varnishes in many cases have proved to be serious enough to offset the principal advantage in using the solventless varnishes for the filling of .open structures.

It is an object of the present invention to pro vide liquid coating and filling compositions which will not drain from objects prior to and during curing.

Another object of this invention is to provide coating and filling compositions which may be applied and cured without loss of the composition.

A further object of the present invention is to provide coating and filling compositions which when applied to objects will remain in situ before and during curing even von corners and sharp edges.

It has been discovered that the advantages in the use of solventless varnishes may be realized in coating and filling operations and at the same time the disadvantage of excessive drainage may be avoided by employing the compositions of this invention. These compositions may be converted by means of heat to an infuslble and insoluble state and are suitable in general for coating and filling operations and particularly for the insulation of electrical equipment. After a, coating of one of the present compositions has been applied to a part, little or no drainage of the composition from the part occurs. either at room temperature or at the elevated temperatures required for complete conversion of the composition to the infusible and insoluble state. The unusual combination of properties'charaoterizing these compositions rests in the discovery that suitable quantitles of certain specific fillers, in combination with solventless varnishes, or ,polymerizable liquids, form compositions which are fluid as long as they are kept in an agitated condition but solidify shortly after agitation has ceased and will not now either at room temperature or at temperatures up to about 150 C.'unless mechanically disitiiirbed before they have hardened by polymeriza- While it is well known that the incorporation of fillers into a varnish will reduce the flow of the resulting mixture by reason or increased viscosity, this general property is not relied upon for the properties of the present compositions. The speciflc fillers which are here employed with solventless varnishes form thixotropic compositions capable oiv undergoing isothermal, reversible, sol-gel transformations, 9. fluid sol condition existing as long as the mixture is agitated, the sol reverting to a gel within a very short time after agitation has ceased.

However, upon heating the gel it polymerizes into an infusible product which is no longer oapable oi reversion into the fluid sol state. The

system may be simply expressed by the following relationship:

At rest Heat Fluid sol 1:2 gel-like solld --u polymerized product Upon agitation The term "thixotropy is used herein to denote the property of a fluid filler liquid composition to revert rapidly on standing into a gel-like mass having sutlicient cohesive strength to withstand distortion by gravitational force when suspended freely as'on an inverted receptacle or on a coated object. The gel is also of such a nature that it can be fluidined by the application of mechanical agitation as by shaking, stirring, vibrating, etc.

The property of thixotrop-y as understood herein is thus characterized by a reversible isothermal sol gel transition.

The compositions referred to above as solventless varnishes which are employed in combination with specific fillers to form the thixotropic composition of this invention are polymerizable fluids comprising an unsaturated alkyd resin. These liquid unsaturated alkyd resins are the reaction products of polyhydric alcohols, mixtures of polyhydric alcohols or mixtures of polyhydric and monohydric alcohols, and an alpha unsaturated alpha, beta polycarboxylic acid or a plurality of poiycarboxylic acids, one of which, at least, is an unsaturated polyoarboxylic acid, the resinous material having an acid value of up to 60 and preferably between 45 and 60. Examples of such polyhydric alcohols are ethylene glycol, diand triethylene glycols, propylene glycol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, glycerine or pentaerythritol in combination with a monohydric alcohoLetc. Examples of alpha unsaturated alpha, beta polycarboxylic acids. are maleic,'fumaric, and itaconic acids. Anhydrides of polycarboxylic acids may also be employed. The term polycarboxylic acid" as used herein is intended to include within its meaning the lanhydrides of such acids. In addition to one or more of the unsaturated polycarboxylic acids. saturated polycarboxylic acids may also be present in the reaction mixture in the preparation of the resins referred to above. Examples of such saturated polycarboxylic acids are succinic, adipic. .Sebacic and phthalic acids.

In additionv to the. above unsaturated alkyd resins, the polymerizable fluids which are used in the present compositions may contain polymerizable substances such as, for example, esters of unsaturated mono-hydric alcohols and polycarboxylic acids, including unsaturated polyoarboxylic acids, halogenated polycarboxylic acids and polybasic inorganic acids. Examples of such substances are diallyl phthalate, diallyl sucoinate, diallyl maleate, diallyl fumarate, diallyl itaconate, dialyl chlorophthalates, and triallyl phosphate. Other substances which may be incorporated in these poymerizable liquids are esters of monohydric alcohols and unsaturated polycarboxylic acids which are capable of copolymerizing with unsaturated alkydresins such as, for example, dioctyl itaconalfi. dibenzyl itaconate, diethyl fuma rate and dibenzyl fumarate.

The thixotropic compositions of this invention may be converted into an infusible, insoluble state by means of heat alone, for example, by curing parts coated or filled with these compositions at temperaturesfrom about C. to about 150 C., or more preferably from about C. to about C. However, for practical reasons, it is desirable to incorporate a polymerization catalyst launc es in order to accelerate the polymerization of the coating or filling compositions. Any of the catalysts known to those skilled in the art may be employed. Examples of such catalysts whichhave been found to be particulaxlysuitableare benzoyl peroxide, tertiary butyl perhenzoate, ditertiary butyl dlperphthalate, and tertiary butyl hydroperoxide. Any suitable amount of catalyst may be used'but ingeneral the catalyst concentration will be within the range of from aboutidh mascot 2.0 percent by weight of the polymerluable liquid.

It has been found that only certain tillers in combination with the above polymoriaahlo 'lidu'ids will afford the th'ixotropic propertiescharacterioing these compositions. -Such fillers will hereinaiter he referred to as "elfective-fillers. Ghlomic oxide (Grails), titanium dioxide (TiOz) ac'icular cine oxide (ZnO) and red iron oxide (Form) in powdered form are particularly effective fillers in our thixotroplc compositions. Other thinetrop'io solventless varnish thixotropic systems are. described in a pending applications Serial Numhers 186,418, 136,412, 136 415, 1136.413, 186 GT, and 186,413, filed concurrently herewith and assigned to the same assignee as the present application.

The degree of thixotropy of the compositions of our invention may be controlled by varying the concentration of eilective filler employed. It the amount of effective filler is too low, no distinct gel formation occurs upon cessation of agitation. As the concentration of effective filler in the compositions is increased, a point is reached where the thixotropic sol-gel transformation becomes apparent. As the concentration of eflective filler is increased beyond this point the composition gradually becomes thicker until a point isreached whereat it becomes so thick that it can be fluidified only with great difilculty. This latter fact is of practical importance since the rate or transformation is a controlling factor in determining the amount of material retained on an oblect upon withdrawal from a bath of one of our compositions. If too much effective filler is employed, the fluidity of the sol drops below the point where practical application or such compositions is feasible. It has been found that, in general, when the above metal oxides are employed as eflective fillers, filler concentrations of from about 40 per cent to about 60 per cent of the total amount or polymerizable liquid and enective filler aflord the preferred range of properties fol-most coating and filling operations.

The degree of 'thutotropy may also becontrolled by varying the amount of moisture in the filler when the latter is of the oxide type. The exact minimum amount of moisture may be found by experimentation and the amounts most suitable for the various fillers are disclosed hereinafter. With the minimum necessary quantity of moisture in the filler, a smooth thixotropic composition is readily attained upon stirring. Lower amounts than the necessary minimum produce 'lumpy compositions which do not smooth out even with continued stirring. On the other hand, higher comentrations of moisture than the necessary minimum. .facilitate the incorporation of the .filler to yield permanently thhiotropic compositions.

Other fillers in addition to the effective fillers referred to above may also be incorporated in the present compositionsin small amounts which do not aftect the thixotropic property. Such fillers are not in themselves capable of affording thlxotropic compositions when mixed with the polymeriwble liquid! "which we employed and are interred to as hon-admins" fillers. Examples or such fillers are sides! or sand, talc, cat-borondum, :ahmdum. .litharue, iron powder, zirconium oxide, calcium tungstate, tungsten oxide, and nickel oxide. However, in combination with effective fillers such non-effective fillers may be used to provide thlxotropic compositions. This offers a convenient method of obtaining .the thixotropio characteristics of the present compositions while retaining a high total filler content and utilizing to advantage whatever outstanding physical property (dielectric, moisture resistance. hardness, tensile strength, toughness, etc.) that the inert .flller may contribute to the final heatpolymeri'zed product.

In .order that those skilled in the art may better understand how the present invention may be carried into effect, the following examples are given by way .of illustration and not by way of limitation, all parts being by weight:

Example 1 Parts Diethylene glycol maleate i will-.. 24.5 Diallyl phthalate fish--5 24.5 Tertiary butylperbenzoate cadmium..- 1.0 Red iron oxide (FeaOc) (dried) 50.0

The above ingredients were thoroughly mixed until a homogeneous mass was obtained. However, the resultant. product, while thixotropic to a. pronounced degree, was lumpy. When water equivalent to aluminium of about 0.3% by weight of the total :aboue ingredients was present, a smooth thixotropic mass was attained. Lesser amounts of water producedlumpy mixtureswhich did not smooth out even after prolonged stirring. 0n the other hand, higher concentrations of water were also found to facilitate the incorporation of the filler into the mixture. A smooth glass rod one-quarter inch in diameter was dipped in the mixture, slowly withdrawn and immediately suspended in a tared container. After sixteen hours at room temperature, .no material had drained from the rod. Neither was any drainage apparent after sixteen more hours at C. during which period cure was effected. This is in direct contradistinction to results obtained with the above composition when no filler was used at all or when a nomefiective filler was used. In both the latter cases only a very small fraction of the original coating remained after the rod was dipped in the material and allowed to hang for sixteen hours at room temperature and was cured for sixteen hours at 100 C. When no water or moisture was present in the red iron oxide filler, about 6% by weight of the coating had drained off after sixteen hours at room temperature. Additional amounts of water over the 0.3 minimum produced favorable results. For example, the water content was 0.9% by weight or the filler, theresults were the same as when 0.3% by weight of water or moisture was present.

Diethylene glycol maleate phthalate was substituted for the diethylene glycol maleate in the above formulation with similar results.

Example 2 Parts Diethylene glycol maleate p'hthalate 33.3 Diallyl phthalate w-l-...... -l 16.4 Ditertlary butyl dlpes'phthalate lei-ll. 0.5 Red iron oxide (FezOs) 325 mesh 49.8

(At least 0.3% H20.)

The above ingredients were mixed together and Passed through a buhrstone mill. The final product exhibited thlxotropic and coating properties similar to those of the composition in Example 1.

Example 3 Parts Diethylene glycol maleate u 2'? Dibenzyl itaconate 9 Diallyl phthalate 9 Tertiary butyl perbenzoate 1 Red iron oxide (F6203) 325 mesh 54 (At least 0.3% H20.)

The red iron oxide was incorporated by stirring into the rest of the ingredients until a smooth, homogeneous mass was obtained. When used to coat a one-quarter inch glass rod, no drainage occurred after standing 17.5 hours at room temper- (At least 0.3% H20.)

The above ingredients were mixed thoroughly until a smooth, homogeneous mixture resulted. This composition was moderately thixotropic in character. A glass rod coated with this material in the manner described in the foregoing examples retained all of the composition picked up during immersion when allowed to stand for 17 hours at room temperature. When the coated rod was baked for 14 hours at 100 0., there was no evidence of any drainage during the baking operation.

Example 5 Parts- Ethylene glycol itaconate ..-o. 2? Diallyl phthalate l8 Tertiary butyl perbenzoate 1. Red iron oxide powder 54 (At least 0.3% H20.)

The above ingredients were thoroughly mixed until a smooth, homogeneous composition was obtained. This composition exhibited pronounced thixotropic properties.

Example 6 Parts Diethylene glycol maleate 28 Diallyl succinate 19 Tertiary butyl perbenzoate 1 Red iron oxide powder 52 (At. least 0.3% H20.)

When the above ingredients were thoroughly mixed, a smooth, uniform composition having pronounced thixotropic properties resulted.

Example 7 Parts Diethylene glycol maleate 36.0 Diallyl phthalate 18.0 Benzoyl peroxide 0.6 Red iron oxide powder 45.4

(At least 0.3% H20.)

The above ingredients were thoroughly mixed into a homogeneous product by passing twice through a, buhrstone mill. The resulting product exhibited pronounced thixotropic properties.

ii ill (At least 0.3% H20.)

A strongly thixotropic composition was ob tained by passing the above ingredients twice through a buhrstone mill.

Chromic oxide (CrzOa) was also found to produoe thixotropic solventless varnish compositions. Whereas in the case of red iron oxide (F6203) is was found that at least 0.3 by weight of moisture was necessary in the filler, it was found that in certain instances satisfactory thixotropic compositions could be made using CI'2O3 when its moisture content was as low as 0.03%. Chromlc oxide of this low water content could be used when using diailyl phthalate alone and certain diallyl phthalate-diethylene glylcol maleate phthalate mixtures. However, there was no limit to the proportions of polymeric material when at least 0.3% moisture in water was present in the chromic oxide.

(At least 0.3% H20.)

The above materials were thoroughly mixed to yield a smooth homogeneous mixture. When a smooth glass rod was dipped into the. mixture, withdrawn and allowed to hang there was no apparent drainage after sixteen hours at room temperature, or an additional sixteen hours at C. On the other hand, when the chromic oxide used in the above example contained only 0.03 it moisture, the mixture was not thixotroplc and almost completely drained from a glass rod which had been dipped in it.

Titanium dioxide was also found to produce thixotropic compositions with solventless varnishes which are suitable for the purposes of the present invention. In general, when the anatase type of titanium dioxide was used, a moisture content of at least 0.2% to 0.3% by weight was required in order to produce an efiective thixotropic composition. A greater amount of moisture merely facilitates the mixing process and does not detract from the characteristics.

(At least 0.2%-0.3% H20.)

The above ingredients were stirred thoroughly to form a smooth, homogeneous'mixmre. A glass rod dipped in the mixture showed n0 drainage of the composition after hanging free-man for sixteen hours at room temperature Drjfilll additional sixteen hours at 100 C. Reasonably greater amounts of moisture than 0.2% to 0.3% in the filler do not detract from the favorable characteristics of the compositions. For example, a mixture made as above, except that the moisture content 01 the filler was 1.2%, wasSuitable for the present use.

Rutile type titanium dioxide also may be used in connection with the present'lnvention. In using rutile type titanium dioxide having at-least 0.2% to 0.3% moisture in conjunction with solventless varnishes, it was found that all materials had drained from dipped glass r'odsin a matter of a few hours. Upon investigation it was found that a water extract of'the-rutile type titanium oxide was alkaline whereas the anatase type titanium dioxide and other oxides described above had acidic water extracts. When the rutile type oxide was treated with a dilute mineral acid, such as hydrochloric acid to make it acidic, i. e. giving an acidic pH to distilled water,

compositions made using it were entirely satisfactory.

Ezcample 11 Parts A B C Diallyl phthalate 23. 22. 0 Diethylene glycol maleate. 23.0 22. 0 Tertiary butyle perhenmate 1.0 l. 0 Rotile titanium dioxide (acid treated) At least 0.2%0.3% moisture) b3, 0 55. 0

The above materials were stirred in the proportions indicated thoroughly to give a smooth mixture which retained its thixotropic properties for several weeks. When a one-quarter inch smooth glass rod was dipped into the above composition and removed, no drainage occurred after sixteen hours at room temperature or after sixteen additional hours at 100 C.

Zinc oxide (2110) of the acicular type may also be used as a thixotrope producing filler for the solventless varnishes set forth in this invention. A water content of at least 0.1% by weight in the filler was found necessary to impart thixotropic properties.

Example 12 Parts Diallyl phthalate 22.0 Diethylene glycol maleate 22.0 Tertiary butyl perbenzoate 1.0 Zinc oxide (ZnO) powder, acicuiar 55.0

(At least about 0.1% H20.)

The above ingredients were easily mixed by stirring into a smooth homogeneous composition. When a one-quarter inch smooth glass rod was dipped into the mixture and removed, no drainage occurred after sixteen hours at room temperature or after sixteen hours more at 100 C.

What we claim as new and desire to secure by Letters Patent oi. the United States is:

1. A thixotropic composition comprising (a) a polymerizabie fluid comprising a liquid unsaturated alkyd resin obtained by the esterification of a mixture of ingredients comprising a polyhydric alcohol and an alpha unsaturated alpha,beta polycarboxylic acid and (b) a moisture-containing filler comprising a metallic oxide of the group consisting of F8203 having a moisture content of at least 0.3 percent, CrzO: having a'moisture content of at least 0.3 percent, ZnO having a moisture content of at least 0.1 percent, and Ti02 having a. moisture content of at least 0.2 percent, the said filler comprising from 40 to 60 percent, by weight, of the total weight 0! the latter and the polymerizabie fluid.

2, A thixotropic composition comprising (a) a polymerizabie fluid comprising (1) a liquid unsaturated alkyd resin obtained by the esterification of a mixture of ingredients comprising 10 a polyhydric alcohol and an alpha unsaturated alpha,beta polycarboxylic' acid and (2) a polymerizable ester of an unsaturated monohydric alcohol and a polycarboxylic acid, and (b) a moisture-containing filler comprising a metallic oxide of the group consisting of F8203 having a moisture content of at least 0.3 percent, CrzOa having a moisture content of at least 0 .3 percent, ZnO having a moisture content of ail-least 011'. percent, and T10: having a moisture content of at least'0;2 percent, the said filler comprising from 40 to 60 percent, by weight, of the total weight of the latter and the polymerizabie fluid.

3. A thixotropic composition comprising (a) a polymerizabie fluid comprising (1) liquid diethylene glycol maleate and (2) diallyl phthalate, and (b) a moisture-containing filler comprising a metallic oxide of the group consisting of F8203 having a moisture content of at least 0.3 percent, CnOa having a moisture content of at least 0.3 percent, ZnO having a moisture content of at least 0.1 percent, and TiOz having a moisture content of at least 0.2 percent, the said filler comprising from 40 to 60 percent, by weight, of the total weight of the latter and the polymerizable fluid.

4. A thixotropic composition comprising (a) a polymerizabie fluid comprising (1) liquid diethylene glycol maleate and (2) a polymerizabie ester of an unsaturated monohydric alcohol and a polycarboxylic acid and (b) a moisture-containing filler comprising a metallic oxide of the group consisting of F6203 having a moisture content of at least 0.3 percent, CI2O3 having a moisture content of at least 0.3 percent, ZnO having a moisture content of at least 0.1 percent, and Ti02 having a moisture content of at least 0.2 percent, the said filler comprising from 40 to percent, by weight, of the total weight of the latter and the polymerizabie fluid.

5. A thixotropic composition comprising a polymerizabie fluid containing liquid diethylene glycol maleate, diallyl phthalate, and a moisturecontainlng filler comprising FeOa having a moisture content of at least 0.3, the said filler comprising from 40 to 60 percent, by weight, of the total weight of the latter and the polymerizabie fluid.

6. A thixotropic composition comprising a polymerizabie fluid containing liquid diethylene glycol maleate, diallyl phthalate, and a moisturecontaining filler comprising CrzOz having a moisture content of at least 0.3 percent, the said filler comprising from 40 to 60 percent, by weight, of the total weight of the latter and the polymerizabie fluid.

7. A thixotropic composition comprising a polymerizabie fluid containing liquid diethylene gly col maleate, diallyl phthalate. and a moisturecontaining filler comprising ZnO having a moisture content of at least 0.1 percent, the said filler comprising from 40 to 60 percent, by weight, of the total weight of the latter and the polymerizabie fluid.

8. A thixotropic composition comprising a polymerizable fluid containing liquid diethylene glycol maleate. diallyl phthalate, and a moistura containing filler comprising TiOz having a moisture content of at least 0.2 percent, the said filler comprising from 40 to 60 percent, by weight, of the total weight of the latter and the poly merizable fluid.

BIRGER W. NORDLANDER. JOHN A. LORITSCH.

(References on following page) 11 12 REFERENCES CITED OTHER REFERENCES The following references are of record in the Industrial Chemistry of Colloidal and Amorfile of this patent: phous Materials" by Lewis, Squires 8.x Broughton, by MacMillan, page (CODY ill 5 scientlfic Library.) Number Name Date Physical Properties of Priming Inks" by 21036-714 Hucks July 1937 Healey, American Ink Maker, May 1943, pp. 22 2,220,621 Ellis NOV. 5, 1940 and 25 26 2,443,736 Kropa. June 22, 1948 2,467,526 Harris J Apr. 19. 1949 10 

1. A THIXOTROPIC COMPOSITION COMPRISING (A) A POLYMERIZABLE FLUID COMPRISING A LIQUID UNSATURATED ALKYD-RESIN OBTAINED BY THE ESTERIFICATION OF A MIXTURE OF INGREDIENTS COMPRISING A POLYHYDRIC ALCOHOL AND AN ALPHA UNSATURATED ALPHA. BETA POLYCARBOXYLIC ACID AND (B) A MOISTURE-CONTAINING FILLER COMPRISING A METALLIC OXIDE OF THE GROUP CONSISTING OF FE2O3 HAVING A MOISTURE CONTENT OF AT LEAST 0.3 PERCENT, CR2O3 HAVING A MOISTURE CONTENT OF AT LEAST 0.3 PERCENT, ZNO HAVING A MOISTURE CONTENT OF AT LEAST 0.1 PERCENT, AND TI02 HAVING A MOISTURE CONTENT OF AT LEAST 0.2 PERCENT, THE SAID FILLER COMPRISING FROM 40 TO 60 PERCENT, BY WEIGHT, OF THE TOTAL WEIGHT OF THE LATTER AND THE POLYMERIZABLE FLUID. 